• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.510-518
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• 2014

Conflicts between humans and wild boars (Sus scrofa) have increased because of causing crop damage and appearing in downtown. Management to reduce population size has mostly been implemented on pests, but knowledges about ecological values are very rare. Rubbing trees by wild boar was investigated to figure out characteristics and for management ecologically from July to October 2013 in a mixed forest, Geochang, Gyeongnam Province, Korea. Pinus rigida was most frequently founded, and rubbing trees, both conifers and deciduous, were mainly located in 200~600 m above sea level. DBH was no significant difference between rubbing and control trees. The use intensity of conifers was higher than that of deciduous. The coverage of foliage layers and the number of woody plants within a radius of 2.5 m of trees (rubbing and control) were also investigated and compared to determine ecological characteristics. There were 1,332 individuals founded from 25 families. In the coverage of foliage layers, the understory and midstory showed statistically significant, but not in the subover and overstory. The number of Shrubs and saplings are higher in rubbing trees than those of control, but no difference in stems. Total individuals, the number of species, species diversity index(H') within a radius 2.5 m is considerably higher in rubbing trees with high intensity than those of low intensity and control. Our results show that wild boar mainly selected and used conifers more frequently as rubbing trees. Wild boar also modified the physical environments around rubbing trees. Consequently, the positive effects such as species diversity is increase. Thus the conservation policies is required after the intensive population reduction every 3-4 years for forest ecological management rather than annual sustainable hunting.

• Journal of Sericultural and Entomological Science
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• v.32 no.2
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• pp.79-84
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• 1990

To make clear the changes of the amount of reserve substances in the bark of stem and root of mulberry graftages after planting, studies were carried with mulberry graftages classified into three groups of 7.0-7.9mm, 9.0-9.9mm and 11.0-11.9mm in diameter of stems at 3cm above their base. The results obtained were as follow : 1. The dry weight of stem and root bark gradually decreased with growth of new shoots till about five weeks after planting, and from then it increased. 2. The duration of new shoots growth depending on the reserve substance was limited for 6-7 weeks after planting. In no fertilized group, the length of new shoots increased up to 6-7 weeks, form then decrease. 3. Dry leaf yield three weeks after planting was found to be no difference in the same diameter of saplings between with and without fertilization. 4. The content of chlorophyll in the leaves was higher in thicker group and in fertilized group than thinner and no fertilized one, respectively. 5. There was no difference in the amount of carbohydrates of the bark of stem and root among the stem diameters. There was a transient increase in the amount of total sugar in the bark of stem and root in the first three weeks after planting, followed by gradual decline up to five weeks. The amount of reducing sugar in the bark of stem and root increased both in fertilized and in no fertilized group up to three weeks after planting, and then it decreased. There was a gradual decline in the content of starch in the bark of stem and root both in fertilized and in no fertilized group up to five weeks after planting, followed by gradual increase.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.33-39
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• 2020

This study was carried out to provide basic information for mass breeding and cultivating the saplings of Camellia japonica. The germination rates did not show definite tendency according to the changes of seed weight at room temperature and 4℃ dry storage conditions. The germination rate of 4℃ wet sand storage was increased with seed weight, but showed very low germination rate for 120 days of storage. The germination rate was above 80% in 60 days, 90 days and 120 days, respectively, at 4℃ wet filter paper storage conditions. The average days taken for those germinations were about 30 days at room temperature and 4℃ dry storage conditions, but wet storage (sand, filter paper) condition took the shortly nearly 13 days for those germinations. Leaf number, leaf dry weight, stem diameter and root dry weight were higher than total average by more than 1.21 g for seed weight. Stem length was higher than the average by more than 1.01 g, plant dry weight was higher than the average by more than 0.81 g, and stem dry weight was higher than the average by more than 0.61 g. In the case of seed weight becoming heavier, seedling growth was good but T/R ratio tended to decrease. In order to increase the mass production of seedlings using Camellia japonica seeds, we need to specify the weight and size of those seeds. The 4℃ wet filter paper storage condition was evaluated as the most efficient method for the seed storage used for seeding.

• 한국해양학회지
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• v.30 no.5
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• pp.426-435
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• 1995

In order to assess the significance of ciliate grazing on bacterial population in carbon flow of the estuarine pelagic ecosystem of the Mankyung and Dongjin river (MD estuary), abundance and biomass of ciliates and grazing rate on bacteria of small (<40 um) ciliates were measured. Saplings were carried out four times from October 1993 to March 1995 in the estuarine system. Ciliates smaller than 40 um occupied more than 49.5% of total ciliates abundance. Clearance rate of small ciliates ranged from 18.0 to 16.3 nl cell/SUP -1/ h/SUP -1/. As bacterial abundance increased, ciliate's clearance rate decreased, suggesting that bacterial abundance effects on ciliate's grazing rate. Ciliate grazing rate was equal to 0.1 to 12.2% of bacterial productivity, and the ratio of ciliate ingestion over bacterial production increased exponentially with the increase of bacterial abundance (r$^2$=0.62, p$\leq$0.001). It seems that the effect of ciliate grazing on bacteria would be small in coastal waters and large in more eutrophic waters of high bacterial abundance. Carbon supplied by ciliate grazing on bacteria was avg. 3.1% of carbon amount required for the ciliate maximum productivity. Thus, the ecological role of ciliate in microbial loop was probably more important as a final consumer than as a direct consumer of bacteria.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.269-276
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• 2005

This research was carried out in order to make clear population and community structure of Berchemia berchemiaefolia forest surveyed from October 1998 to October 2004 which was located in Janggok-Ri Gunwi-Gun, Kyungpook province. B. berchemiaefolia community was classified into 3 groups such as Picrasma quassioides group, Carex ciliata-marginata group and Typical group using ZM methods. In case of floristic composition structure according to crown stories, B. berchemiaefolia occupied 42.82%, 34.43%, and 5.28%, in tree layer, subtree layer and shrub layer, respectively. Importance value of Quercus variabilis, Platycarya strobilacea and Quercus serrate species was generally high. Species diversity of Picrasma quassioides group indicated 1.6669 which was highest value among the 3 vegetation groups. Population of B. berchemiaefolia showed overall the structure of reverse J type in DBH class showing the peak between 6 cm and 10 cm and reached 14 meters in height class, and the age structure of the population ranged from 11 years to 60 years showing regular distribution type. Stump sprout or/and epicormic branch made numerous stems around original stump of previous generation which was considered to be cut and disappeared by residents. Seedlings or/and saplings of B. berchemiaefolia were intensively occurred in the opened areas of forest road. Those things could be certainly considered to establish management plan of B. berchemiaefolia forest.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.445-458
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• 1998

The present study focused on the vegetation structure and dynamics of Betula davurica forest were to provide the information for management, distribution and utilization of B. davurica forest in Mt. Chiri national park, southern Korea. The layer structure of B. davurica forest were consist of tree layer(18 species), middle layer(29 species), shrub layer(43 species) and herb layer(68 species). According to the importance value of stratification of layers, In tree layer, B. davurica dominant the highest value of 123.97%, Alnus hirsuta 49.04., Castanea crenata 25.58%, Quercus serrata 25.02%, Stewartia koreana 14.49%, in middle layer were B. davurica 70.81%, Q. serrata 37.74%, Fraxinus rhynchophylla 25.35% Lindera erythrocarpa 24.52%, S. koreana 18.86%, shrub layer were Sasa borealis 28.28%, L. erythrocarpa 24.94%, Rhus trichocarpa, 20.42%, Stephanandra incisa 19.90% and herb layer Schizandra chinensis 18.51%, Aster scaber 12.26%. Disporum smilacinum 10.63% etc, respectively. Results of chi-square test statistics based on presence-absence parameters, the positively associated species pair were Quercus variablis - Q. acutissima, Stewartia koreana - Symplocos paniculata, Acer pseudo-sieboldianum - Quercus mongolica. And covariation was calculated based on quantitative measure of density. The results showed that the association and covariation values among species not agreed with each other. The frequency distribution of DBH Betula davurica species showed reverse J-shaped, therefore it's seems to retrain as a dominant species. When predicting succession in Betula davurica forest, it is seedling and saplings were not richness, succession was governed by competition of hardwood species of subtree and tree layer.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.221-228
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• 1994

Respitation and growth rates of leaves, branches, stems and roots of 2 to 11-yr-old red pine trees(Pinus densiflora) were examined and applied to Thornley's growth equation, $$R=(\frac{1-Yg}{Yg})\frac{dW}{dt}+mW$$. The conversion efficiency of substrates(Yg), maintenance respiration coefficients(m), relative growth rates(${\mu}$) were estimated. The efficiency of conversion of substrates (Yg) was 0.3637g/g dw/yr and the maintenance respiration coefficient(m0 was 0.094g/g dw/yr. The relative growth rate(${\mu}$) was remarkably reduced with age from 0.90(2-year-old) to 0.33:11 year-old). The Ratio of gross respiration(R) per gross photosynthesis(Pg), R/Pg showed the range of 0.6~0.7 and annually 64% of Pg was spent for constructive respiration. The 3.4% of dry weight of whole tree was spent for maintenance respiration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.296-302
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• 2005

We investigated changes in photosynthetic characteristics of P. davidiana in order to understand damage patterns to photosynthetic apparatus under drought stress. Root sprout saplings of P. davildiana were treated with $0\%,\;2\%,\;5\%,\;and\;10\%$ of 300ml polyethylene glycol (PEG) once a weer far one month. After one month, we measured photosynthetic parameters and analyzed the photochemical and $CO_2$ fixation systems. Photosynthetic rate, stomatal conductance, and respiration rate in the leaves of P. davildiana decreased according to increasing stress strength. In the photochemical system, quantum yield of PSII was reduced by the increment of PEG concentration, The decrease of apparent quantum yield was related to reduction of electron transport. Respiration rate decreased with an increase in PEG concentration, whereas photorespiration rate in the $CO_2$ fixation system increased. In conclusion, photosynthesis of P. davidiana responded sensitively under drought stress, and the sensitivity depended upon the strength of water stress. P. davidiana exhibited an increase of water use efficiency under water stress.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.260-270
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• 1996

Structure and dynamics of Pinus densiflora community in Mt. Kaya were studied to provide the information needed for management of Pinus densiflora forest in the southern inland of Korea. Stratification structure of Pinus densiflora community in the lower and middle slope consisted of tree layer(10~15m), subtree layer(4~10m), shrub layer(1~4m), and herb layer(below 1m), while in the rock zone of ridge and top area consisted of tree layer(7~10m), subtree layer(2~7m), shrub layer(1~2m), and herb layer(below 1m). According to the diameter distribution of tree species in Pinus densiflora community, secondary Pinus densiflora forest will gradually decline. Its forest may be replaced by Quercus mongolica, Quercus serrata, Carpinus laxiflora, C. cordata, and Fraxinus rhychophylla in the lower slope, and by Quercus mongolica in the middle slope. Pinus densiflora forest has its seedlings and saplings in ridge and top area, so it may be sustained. By taking cores from Pinus densiflora trees in research area, it could be obtained that in the lower and middle slope, age of Pinus densiflora forest was about 80~90 years old. When the age of its trees was about 72~80 years old, withering trees of standing dead occurred. Disturbance regime of Pinus densiflora community in Mt. Kaya consisted of standing dead, uprooting and limbfall, these were 70.6%, 17.6% and 11.8% respectively. It takes about 100~110 years for advance growth of Pinus densiflora in ridge and top area to reach tree layer. During the period, it has twice chances of disturbance in standing dead. Annual diameter growth of Pinus densiflora was 2.45~2.9mm in the lower and middle slope, while it was 1.75mm in ridge and top region, by measuring cores.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.419-424
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• 2007

The urban forest offer many opportunities to maintain and enhance local and regional biological diversity. Pinus densiflora stands in isolated urban forest in five areas of Seoul, Incheon, Daegu, Ulsan, and Cheongju were investigated by landscape and community ecological methods for diagnosis of current status and construction of conservation plan. Species composition of five study areas revealed regional characteristics. As the result of stand dynamics, absence of pine seedlings and saplings were observed. Cheongju, significantly, revealed highest species diversity (H'=1.86) and richness (24) among study areas, and the opposite was true for Daegu (1.35 for H', and 14 for richness). Ratio of alien species was highest in Daegu (15.8%) (F=5.05, p=0.0016). Based on landscape analysis, complexity of pine patch was higher in local city than metropolitans, but statistically not significant (p=0.133). Complexity of pine patch revealed significant positive correlation with diversity and richness, but not with percentage of aliens. Synthetically, ecological management based on community and landscape ecological information was recommended. Cautious artificial regeneration strategy was necessary to regenerate pine forest in urban area.